It seems like it could be a fun concept, but I was unable to play the game is it was supposed to, although you probably already knew about these points, I'm still going to list them in case you didn't. :D
- The speed,jumpheight and gravity seem a bit fast, I'm assuming it was correct at runtime, but you may have forgotten to use Deltatime?
- Due to the fast gravity, my character got stuck inside the block alot after dying.
- I'm not sure whether this is the case, but it seems like I started near the middle or the end of the level, seeing as I'm also able to go left for a while.
- When I reach (the presumed) end, with the giant (once again I presume) endboss, nothing happens.
Though obviously still unfinished (which if fine, my game is also still unfinished), it seems like it could turn out pretty good if you continue working on it.